Rotary pump for hydrodynamic lubrication



April 1954 J. BOUVAT-MARTIN 2,674,503

ROTARY PUMP FOR HYDRODYNAMIC LuBRmTIoN Filed April 22, 1952 2 Sheets-Sheet l 7 Fig .1. 26

'22 26 A 1a Fig.6.

Fig.2. 19 Y R I 20 2| 0 8 i R "/6 r [m/enfw" Jew/7 504/, vafi Marf/l? April 6, 1954 J. BOUVAT-MARTIN 2,874,503

ROTARY PUMP FOR HYDRODYNAMIC LUBRICATION Filed April 22, 1952 2 Sheets-Sheet 2 Fig.3.

In van/0W Jean 500/ 1/4 Ma "7727 Patented Apr. 6, 1954 UNITED STATES PATENT OFFICE ROTARY PUMP FOR HYDRODYNAMIC LUBRICATION Jean Bouvat-Martin, Paris, France, assignor to Societe Anonyme dite:

1 It is known that the lubrication of plain bearings cannot be effected under proper and satisfactory conditions if a continuous oil film is not formed and maintained between journal and bearing, according to the thearetical requirements of hydrodynamic lubrication.

A particular problem arises in connection with the lubrication of railway-stock axle-boxes; it is not possible to submerge the axle spindle in an oil bath because the desired complete oiltightness and long useful life of an oil-bath axlebox are hardly obtainable in railway engineering. Consequently, it must be admitted that in The fact that this lubricating oil must pass through astrainer so that only clean oil will be supplied to the spindle involves the use of a pump enclosed in the axle-box itself, mechanically driven by the axle and adapted to operate at least under a low pressure.

The demand for a pump designed to operate in both directions of rotation had set the hitherto wide-spread trend of piston-pumps, but anybody conversant with the art has to admit that they lack sturdiness and are ill-suited for heavy-duty conditions as commonly encountered in railway operation.

Now, it is the object of this invention to provide a-rotary pump adapted to meet the abovelisted requirements, the two-way operation of the pump according to this invention being obtained by means of a distributor combined with the pump-driving shaft.

The pump-driving shaft is actuated by a member rotatably rigid with the spindle and carrya vertical or oblique shaft fixed with the oilpumping vane.

This driving shaft may slide axially in its casing formed in the pump body between two extreme positions wherein the oil-intake duct of the bearing is in fluid connection with either of two oil-delivery ducts that lead from the chamber of the rotary pump vane.

According to the direction of rotation of the spindle, this shaft will first move axially toward either of the aforesaid two outermost positions, thereby connecting automatically the appropriate oil-delivery duct with the pumping circuit.

This arrangement is extremely simple, safe and economical; it makes it possible to use a rotary pump in an axle-box irrespective of the direction of movement of the vehicle and without any undue complications.

Societe General Iso- The accompanying drawings forming part of this specification illustrate diagramatically by way of exampe a few embodiments of the invention. In the drawings:

Figure 1 is a longitudinal section of the front portion of an axle-box;

Figure 2 is a similar vertical view showing the device in another operative position;

Figure 3 is a cross-sectional view taken across the line IIIIII of Fig. 1;

Figure 4 is a sectional view taken along the line IVIV of Fig. 3;

Figure 5 is another sectional view according to the line VV of Fig. l, and

Figure 6 is a sectional detail view according to the line VIVI of Fig. 5.

a strainer of filter l with the bottom or sumpforming portion of the axle-box; the inner end [3 of th driving shaft 2 has fixed thereon a strap like member l4 rotatably driven by a crank-pin I5 fixed eccentrically to th outer end or head I 6 of a screw or other cap member fixed endwise of the spindle [2; the axial displacement of the horizontal driving shaft 2 is restricted in one direction by an abutment nut 8 acting also as a bearing member and in the other direction by a shoulder formed in the bottom of the chamber in which the helical pinion 3 rotates; l8 and I 9 designate a pair of oil-delivery ducts connecting the pump chamber I7 to a pair of ports 20, 2|. According to the axial position of shaft 2, the fluid connection is established between chamber l7 and a delivery duct 22 through either of these ports 20 and 2|, the delivery duct 22 being adapted in turn to deliver oil to a pool 23 formed in the upper portion of the bearing II.

The above-described device operates as follows:

(a) Clockwise rotation (as seen in Fig. 3)

The horizontal driving shaft 2 is shifted from right to left (see arrow F, Fig. 1) and abuts the left-hand shoulder or wall of its chamber in the pump body I. It therefore closes the delivery port 20 and uncovers the other delivery port 2|, thereby connecting the oil-delivery duct IS with the delivery duct 22 through a reduction 25 in the diameter of shaft 2.

The vertical shaft 4 is then driven by pinion 5 and rotates clockwise. The pump vane 6 forces oil from" the strainer 1 and intake 24 through both ducts l9,'22 the latter-being formed in the front cover of the axle-box.

(b) Anti-clockwise rotation (as seen in Fig. 3)

The horizontal driving shaft2 is shifted from left to right (see arrow 3, Fig. 2) and abuts against the right hand guide nut 8,1,therebyobturating the delivery duct I9 and :opening the delivery duct 18.

Then, the vertical shaft t-is rotatablydri-ven by pinion 5 and rotates in the opposite direction; the pump vane 6 draws in oil through the strainer 'i and intake duct 24 and delivers same across both ducts l8 and 22, thereby supplying clean oil to the pool 23 of bearing ll.

It will be seen that irrespective of the direction of movement of the vehicle and therefore of rotation of the spindle l2, the shaft 2 of the device according to the invention, which is constantly driven by the crank pin 15 slidably engaged in the notch formed in the member l4 rigid with this shaft, will first move axially in the direction of either of arrows F or 1, thereby connecting either of the oil-delivery ducts [8 or IS with the duct 22 through which oil from the bottom of the axle-box is supplied to the pool 23 of bearing ll.

What I claim is:

A pump mounted in an axle-box of railway vehicle for feeding the lubricating pool of the bearing mounted on the spindle with oil from the bottom of said axle box, said pump comprising a pump body formed with a cavity, a shaft mounted for rotation about a horizontal axis in said cavity and adapted to slidezlongitudinally i between .two end positions, :means forev drivingly connecting said shaft from said spindle for rota- ;tion therewith, a helical pinion fast on said shaft in said cavity, another shaft mounted for rotation-about a'vertical axis in said body, another helical pinion fast on said other shaft and meshing with said first helical pinion, a vane ext-endingrradiallyifrom and rigid with said other shaft inthe vicinity of said bottom of said axle b.ox,,the.,pump body being crossed by two inner channels, each of said channels having a cross passage throughlthemavity, a lower aperture positionedin the bottom of the axle box and an upper aperture, and leading to the upper aperture the oil driven by the vane in the lower aperture when the spindle andboth shafts rotate in one direction, the first shaft being then-moved by the reaction of the other pinion against the first pinion to one of its end positions andthe first shaft occluding, in said end position, the cross passage of the other channel in the cavity, and a duct leading to the lubricatingpool the oil issuing from anyone of both channels.

References Citedin the file of this patent FOREIGN PATENTS Number Country Date 326,993 Italy July 1, 1935 684,908 France June. 2, 1930 

